[TechNote] HTTP Plug-in failures might prevent IBM HTTP Server from starting

HTTP Plug-in failures might prevent IBM HTTP Server from starting

Problem(Abstract)

There are several reasons that could cause the HTTP plug-in to fail to load or fail routing requests to the WebSphere Application Server. These are the 2 possible errors that might occur: 

1. The plug-in cannot use DNS to resolve the server hostnames listed in the plug-in configuration file.

2. The plug-in log file is larger then 2GB.

If either of these errors occur, the failure will also prevent the IBM HTTP Server from starting.

Symptom

The plug-in log might contain errors such as the following:

ws_transport: transportSetServerAddress: Failed to resolve address ws_server: serverAddTransport: Failed to initialize server address ws_config_parser: configParserParse: Failed to parse the config file ws_common: websphereUpdateConfig: Failed parsing the plugin config file

These errors are an indication that the plug-in cannot use DNS to resolve the hostnames of the WebSphere Application Servers defined in the plug-in XML file.

These errors will cause the HTTP plug-in to not load. This failure prevents the HTTP server from starting.

Cause

The plug-in at load time verifies connectivity to the WebSphere Application Servers defined in the plug-in config file. If no connectivity to the servers exists, then the plug-in will fail to load.

This behavior can be changed by setting the value for IgnoreDNSFailures="true"

• Web server plug-in configuration properties
• plugin-cfg.xml file

The other possible cause of a load problem is a plug-in log file that is larger then 2GB. Simply check the size of the plug-in log to see if it has in fact reached the size of 2GB. If it has, then delete or rename the log.

Resolving the problem

The problem can be resolved by insuring that the system on which the plug-in is running can successfully resolve the hostname of the WebSphere application servers defined in the plug-in config file.